THE PERNICIOUS SCALE INSECT IN 

 NEW HAMPSHIRE. 



BY CLARENCE M. WEED. 



The San Jos^ or Pernicious Scale has attracted more atten- 

 tion from American fruit growers during the last ten years than 

 any other insect. It Jias been recognized as a most dangerous 

 pest which was likely to be introduced into any community 

 through the sale of young trees. It was apparently first intro- 

 duced into New Hampshire at Manchester about ten years ago, 

 but it has been repeatedly introduced since on trees brought 

 from nurseries in other states. It is now known to be present 

 in the following New Hampshire cities and towns, and probably 

 is found in several others: Dover, Durham, Eppiug, Intervale, 

 Manchester, Eollinsford, Seabrook. 



The presence of the Pernicious Scale is difficult to detect 

 until it becomes sufficiently abundant to injure or kill the in- 

 fested tree. It then appears as a curious scaly crust on the 

 bark. When only a few are present it is difficult to find them, 

 as they are simply small round spots of much the same color as. 

 the bark, to be seen plainly only through a magnifying glass. 

 Their presence generally is not discovered for two or three sea- 

 sons after they first appear, by which time they have usually 

 spread to surrounding trees. 



The individual scale is a small round object closely attached! 

 to the bark, not more than one eighth of an inch in diameter 

 and having a darker raised point near the center. At first these 

 round scales are likely to be scattered here and there over the 

 bark, but as they increase in numbers they are nearer together, 

 touching or overlapping one another, and perhaps finally mak- 

 ing a thick, scurfy layer of a grayish color that obscures the 

 natural color of the bark, and is easily rubbed off with the fin- 



